System for managing scheduling conflicts

ABSTRACT

A system that incorporates teachings of the present disclosure may include, for example, a proactive scheduler having a controller element to determine a scheduling conflict between a called party and a calling party according to calendar information of the called party and presence information of the called party. Additional embodiments are disclosed.

FIELD OF THE DISCLOSURE

The present disclosure relates generally to communication systems, andmore specifically to a system for managing scheduling conflicts.

BACKGROUND

Electronic organizers such as a calendar feature in Personal DigitalAssistants (PDAs) have become very popular with professionals who havebusy schedules. These devices help professionals manage their timeeffectively and remove the burden of memorization and the use ofpaper-based organizers. Notwithstanding the popular use of organizers,scheduled events (professional or personal) are not always accurate intheir duration or start times. Consequently, many users of electronicorganizers have to resort to real-time rescheduling and at times requirethe manual assistance of a secretary to reorder scheduled events.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts an exemplary embodiment of a communication system;

FIG. 2 depicts an exemplary method operating in portions of thecommunication system; and

FIG. 3 depicts an exemplary diagrammatic representation of a machine inthe form of a computer system within which a set of instructions, whenexecuted, may cause the machine to perform any one or more of themethodologies disclosed herein.

DETAILED DESCRIPTION

In one embodiment of the present disclosure, a computer-readable storagemedium can have computer instructions for retrieving a called partynumber and a calling party number from a communication session,identifying a calling party according to the calling party number,identifying a called party according to the called party number,retrieving calendar information of the called party, detecting in thecalendar information a scheduled event associated with the callingparty, retrieving presence information of the called party, anddetecting a conflict between the scheduled event and the presenceinformation of the called party.

In one embodiment of the present disclosure, a proactive scheduler canhave a controller element to determine a scheduling conflict between acalled party and a calling party according to calendar information ofthe called party and presence information of the called party.

In one embodiment of the present disclosure, a presence system can havea controller element to present a scheduler presence information of acalled party to determine a scheduling conflict between a calling partyand the called party according to calendar information associated withthe calling party and called party and said presence information.

FIG. 1 depicts an exemplary communication system 100. The communication100 can comprise a Subscriber Services System (SSS) 121, a HomeSubscriber Server (HSS) 140, a tElephone NUmber Mapping (ENUM) server130, and network elements of an IP Multimedia Subsystem (IMS) network150. The IMS network 150 can be coupled to IMS compliant communicationdevices (CDs) 101, 102 or a PSTN CD 103 using a Media Gateway ControlFunction (MGCF) 120 that connects the call through a common PSTN network160.

IMS CDs 101 and 102 register with the IMS network 150 by contacting aProxy Call Session Control Function (P-CSCF) which communicates with acorresponding Serving CSCF (S-CSCF) to register the CDs usingAuthentication, Authorization and Accounting (AAA) with the HSS 140. Toaccomplish a communication session between CDs, an originating IMS CD101 can submit a SIP INVITE message to an originating P-CSCF 104 whichcommunicates with a corresponding originating S-CSCF 106.

The originating S-CSCF 106 can submit the SIP INVITE message to anapplication server (AS) such as references 110 and 115 to provide avariety of services to IMS subscribers. For example, the applicationserver 115 can be used to perform originating treatment functions on thecalling party number such as determining whether the calling partynumber has international calling services, and/or is requesting specialtelephony features (e.g., *72 forward calls, *73 cancel call forwarding,*67 for caller ID blocking, and so on).

Additionally, the originating S-CSCF 106 can submit queries to the ENUMsystem 130 to translate an E.164 telephone number to a SIP UniformResource Identifier (URI) if the targeted communication device is IMScompliant. If the targeted communication device is a PSTN device, theENUM system 130 will respond with an unsuccessful address resolution andthe S-CSCF 106 will forward the call to the MGCF 120 via a BreakoutGateway Control Function (not shown).

When the ENUM server 130 returns a SIP URI, the SIP URI is used by anInterrogating CSCF (I-CSCF) 107 to submit a query to the HSS 140 toidentify a terminating S-CSCF 114 associated with a terminating IMS CDsuch as reference 102. Once identified, the I-CSCF 107 can submit theSIP INVITE to the terminating S-CSCF 114 which can call on anapplication server similar to reference 115 to perform the originatingtreatment telephony functions described earlier. The terminating S-CSCF114 can then identify a terminating P-CSCF 116 associated with theterminating CD 102. The P-CSCF 116 then signals the CD 102 to establishcommunications. The aforementioned process is symmetrical. Accordingly,the terms “originating” and “terminating” in FIG. 1 can be interchanged.

The SSS 121 can be used to provide an assortment of additional servicesto a subscriber of for example a proactive scheduler operating as anapplication server (PSAS) 110 in the IMS network 150. The PSAS 110 canfunction as a sub-element of a unified messaging system. Serviceelements of the SSS 121 can include for example a voicemail server 122,a contact (or address) book server 124, a calendar server 126, and apresence server 128, among other possible systems. Each of these serversutilizes common computing and communication technology to exchangemessages with the PSAS 110 in accordance with the present disclosure.

FIG. 2 depicts an exemplary method 200 operating in portions of thecommunication system 100. Method 200 begins with step 202 in which acalling party directs a call to a called party by way of a communicationdevice (IMS 101 or 102, or PSTN 103). During the call setup process theterminating S-CSCF 114 can convey in step 204 the SIP INVITE message tothe PSAS 110 thereby informing it of the incoming call. The PSAS 110 canretrieve a calling party number and called party number from the SIPINVITE message to identify in step 208 the calling party and the calledparty. The called party can be identified by the PSAS 110 by matchingthe called party number to an entry in a database accessible to the PSAS110. The database can reside in the PSAS 110 or can be distributed inone or more network elements of the communication system 100 accessibleto the PSAS 110. Once a match is found, the PSAS 110 can determine whichservices are available to the called party subscriber. Once the calledparty has been identified, the PSAS 110 can identify the calling partyusing any of several methods such as by matching the calling partynumber (or caller ID) to an entry in a contact book account of thecalled party managed by the contract book server 124. The contact bookaccount can for example provide the PSAS 110 one or more names of thecalling party (first name, nickname, surname and so on).

In step 210, the PSAS 110 can retrieve presence information of thecalled party from the presence server 128. Presence information canprovide status information that indicates for example where the calledparty may be located, and/or which of a number of communication devices(e.g., cell phone, laptop computer, office phone, home phone, etc.)available to the called party are being used by said party.

The location of the called party can be determined a number of ways. Forinstance, location coordinates can be supplied by one or more of thecommunication devices of the called party using Global PositioningSystem (GPS) technology. The called party can also be located by commontriangulation techniques. The location can also be correlated with knownstructures. For example, a location coordinate can indicate the calledparty is in his/her home, office, conference room of office building,and so on.

Presence information can also identify which of the communicationdevices available to the called party is being used by said party,and/or the most probable device from which a party can initiatecommunications with the called party. For example, if the called partyis at his/her desk working on a desktop computer, the presence servercan detect the called party's presence in an office by a proactivemessage supplied by the computer, or by detecting network activityemanating from the computer. The presence server can be configured toknow that in the location of the desktop computer the called party alsohas an office phone. The presence server can also detect when the calledparty is traveling. For instance, the presence server can detect that acell phone roaming from base station to base station. In this instance,the presence server can detect that the called party is in anautomobile. Similarly, the presence server can detect that the calledparty is in different times zones (domestic or international).

From the foregoing examples, it would be evident to an artisan withordinary skill in the art that the presence server 128 can utilize knownand future techniques to identify the location and/or activities of aparty having a plurality of communication means.

In step 212, the PSAS 110 can determine if the calling party has enteredan emergency access code, has a communication priority level or assignedcommunication preference previously entered by the called party forredirecting calls. The priority or preference can be included in acontact book entry associated with the calling party which is stored andmanaged by the contact book server 124. A priority or preference can beentered by the called party to address calls from specific callingparties in different ways. For example, calls from the called party'smanager should always be redirected to the called party's cell phone.Calls from a spouse or children during work hours should be directed toan office number. All other calls should be processed according to steps214-230. The emergency access code can be for example a sequence of DualTone Multi-Frequency (DTMF) entries (e.g., *8) made by the calling partyto identify the call as an emergency call that needs to be directed tothe called party independent of who the calling party is. The PSAS 110can process the DTMF sequence and detect that it corresponds to anemergency access code.

Accordingly if a call redirection is detected, the PSAS 110 proceeds tostep 214 where it redirects the call according to preferences givenand/or presence information of the called party. For instance if thecalling preferences dictate calls to a cell phone, but the presenceinformation indicates that the cell phone of the called party is off,then the call will be redirected to another communication device of thecalled party having the highest probability of reaching said party. Incases where more than one communication device has a similar probabilityof reaching the called party, the PSAS 110 can redirect the call fromone communication device to the next until the called party is reached.If none of said devices reach the called party, the calling party can bedirected to the voicemail server 122 to leave a voicemail message forthe called party.

If call redirection is not required, the PSAS 110 proceeds to step 216where it retrieves calendar information of the called party from thecalendar server 126. The calendar information can represent one or moredays, weeks or months worth of calendar events associated with thecalled party. The calendar period retrieved can start on the day whichthe calling party makes the call or some other suitable time. The amountof calendar information retrieved by the PSAS 110 is a policyconsideration which can be configured by a service provider of the PSAS.In step 218, the PSAS 110 can determine from the calendar informationwhether there is a scheduled event between the calling party and thecalled party. This detection can take place for example by matching thename or caller ID of the calling party retrieved in step 208 withinformation supplied in the calendar event.

For example, a calendar event previously entered by the called partymight say “Discuss milestones with Joe Doe” in which Joe Doe is to callthe called party at 3 pm Central time. The list of invitees and/or thetext portion ‘Joe Doe’ in the calendar event can be matched by the PSAS110 with the name, nickname and/or surname of the calling partyretrieved in step 208 to determine that there is a schedule eventbetween the calling party and the called party at 3 pm Central time. Ifno scheduled event is detected in step 218, the PSAS 110 proceeds tostep 219 where the call is directed to the called party by networkelements of the IMS network 150 as originated by the calling party. Ifthe called party does not answer, the PSAS 110 can direct the callingparty to the voicemail system 122.

Otherwise in step 220, the PSAS 110 can determine whether there is ascheduling conflict based on the presence information retrieved in step210. For example, the presence information can indicate that the calledparty is still actively engaged in a conference call. Additionally, thecalled party can proactively notify the presence server 128 that s/hewill be 20 minutes late to the next meeting. This proactive notificationcan be the result of on an email or other messaging means (e.g., SMS,MMS, instant messaging, or otherwise) between the called party and thepresence server 128 to provide said system additional statusinformation. If no conflict is detected, the PSAS 110 proceeds to steps219 and 226 as described earlier.

When a conflict is detected, the PSAS 110 can proceed to step 222 toinform the calling party of the conflict utilizing common speechsynthesis techniques (e.g., “I understand that you have a meetingscheduled with Mr. Doe at 3 pm. Unfortunately, Mr. Doe is running latewith his current meeting.”). The PSAS 110 in step 224 can then determinefrom the calendar entries of the called party if an alternative time isavailable. The alternative time can arise from an unused time slot inthe called party's calendar, or can be the result of the PSAS 110shifting the called party's appointments based on the expected time ofdelay from the present meeting. Whether or not the PSAS 110 shiftsexisting appointments can be a preference established by the calledparty. The preference can be applied to all parties, or can beselectively applied depending on who the calling party is. Moreover thepreferences can be in whole or in part stored and managed by the PSAS110 and/or entries from the called party's contact book.

If for example the preference established for the calling party is suchthat the PSAS 110 cannot reschedule other appointments of the calledparty, and the called party's calendar has no available time slotsduring working hours to reschedule a call with the calling party, thenthe PSAS 110 can direct the calling party in step 226 to the voicemailsystem 122 under the assumption the presence information would indicatethe called party does not want to be disturbed. If the called party iswilling to accept calls at all times, the PSAS 110 can be configuredinstead to proceed to steps 219 and 226 as described earlier. If on theother hand, the preference established for the calling party is suchthat other appointments can be rescheduled and/or the called party hastime slots available, the PSAS 110 can proceed to step 228 where itproposes to the calling party an alternative time for the scheduledappointment (e.g., “Would it be possible to reschedule your appointmentwith Mr. Doe to 3:30?”) utilizing common speech synthesis and voicerecognition techniques (much like those used by an interactive voiceresponse system).

If the calling party accepts the proposal in step 230 by DTMF or voicedetection (e.g., press 1 or say “yes”), the PSAS 110 can reschedule theappointment in step 232 according to the alternative time selected. Tomaintain an updated calendar schedule, the PSAS 110 can direct in thisstep the calendar server 126 to update its database for the called partyaccording to the rescheduled appointment. After step 232, the call canbe terminated by the calling party, or the calling party can be directedby the PSAS 110 to complete the call in steps 219 and 226 as describedabove. Proceeding to step 219 can be an option proposed to the callingparty by the PSAS 110 utilizing a common interactive voice responsesystem.

If on the other hand the calling party does not accept the proposedalternative time, the PSAS 110 can proceed to step 224 where itdetermines another time and/or asks the calling party to propose a timethat works for him/her. Steps 224, 228 and 230 can be iterative untilthe PSAS 110 satisfactorily determines an alternative appointment timewith the calling party or transfers the calling party to the voicemailsystem in step 226 if a resolution cannot be determined or if voicemailis requested by the calling party.

Upon reviewing the aforementioned embodiments, it would be evident to anartisan with ordinary skill in the art that said embodiments can bemodified, reduced, or enhanced without departing from the scope andspirit of the claims described below. For instance, the presentdisclosure can be applied in a PSTN only communication system that doesnot utilize IMS or VoIP communications. Method 200 can have more or lesssteps and in different order without adversely affecting the presentdisclosure.

Other appointment resolution techniques can also be applied to thepresent disclosure. For instance, when a conflict is detected and thecalling party is informed, the calling party can submit a signal to thePSAS 110 of the called party to redirect the call to a PSAS of thecalling party so that two automated systems can proactively resolve theconflict based on the called party's and calling party's calendars andpresence data. The signal can be the calling party's unified messagingnumber or the caller ID entered with a DTMF sequence or spoken.Alternatively, the PSAS 110 can recognized that the calling party isalso a subscriber of the same system and can offer the calling party theoption to automatically resolve the conflict with or without the callingparty participating in the resolution. In this embodiment, once theconflict is resolved, the calendars of the called party and callingparty are updated respectively without manual interaction from eitherparty.

Other suitable modifications can be applied to the present disclosurewithout deviating from the scope of the claims. Accordingly, the readeris directed to the claims section for a fuller understanding of thebreadth and scope of the present disclosure.

FIG. 3 depicts an exemplary diagrammatic representation of a machine inthe form of a computer system 300 within which a set of instructions,when executed, may cause the machine to perform any one or more of themethodologies discussed above. In some embodiments, the machine operatesas a standalone device. In some embodiments, the machine may beconnected (e.g., using a network) to other machines. In a networkeddeployment, the machine may operate in the capacity of a server or aclient user machine in server-client user network environment, or as apeer machine in a peer-to-peer (or distributed) network environment.

The machine may comprise a server computer, a client user computer, apersonal computer (PC), a tablet PC, a laptop computer, a desktopcomputer, a control system, a network router, switch or bridge, or anymachine capable of executing a set of instructions (sequential orotherwise) that specify actions to be taken by that machine. It will beunderstood that a device of the present disclosure includes broadly anyelectronic device that provides voice, video or data communication.Further, while a single machine is illustrated, the term “machine” shallalso be taken to include any collection of machines that individually orjointly execute a set (or multiple sets) of instructions to perform anyone or more of the methodologies discussed herein.

The computer system 300 may include a processor 302 (e.g., a centralprocessing unit (CPU), a graphics processing unit (GPU, or both), a mainmemory 304 and a static memory 306, which communicate with each othervia a bus 308. The computer system 300 may further include a videodisplay unit 310 (e.g., a liquid crystal display (LCD), a flat panel, asolid state display, or a cathode ray tube (CRT)). The computer system300 may include an input device 312 (e.g., a keyboard), a cursor controldevice 314 (e.g., a mouse), a mass storage medium 316, a signalgeneration device 318 (e.g., a speaker or remote control) and a networkinterface device 320.

The mass storage medium 316 may include a computer-readable storagemedium 322 on which is stored one or more sets of instructions (e.g.,software 324) embodying any one or more of the methodologies orfunctions described herein, including those methods illustrated above.The computer-readable storage medium 322 can be an electromechanicalmedium such as a common disk drive, or a mass storage medium with nomoving parts such as Flash or like non-volatile memories. Theinstructions 324 may also reside, completely or at least partially,within the main memory 304, the static memory 306, and/or within theprocessor 302 during execution thereof by the computer system 300. Themain memory 304 and the processor 302 also may constitutecomputer-readable storage media.

Dedicated hardware implementations including, but not limited to,application specific integrated circuits, programmable logic arrays andother hardware devices can likewise be constructed to implement themethods described herein. Applications that may include the apparatusand systems of various embodiments broadly include a variety ofelectronic and computer systems. Some embodiments implement functions intwo or more specific interconnected hardware modules or devices withrelated control and data signals communicated between and through themodules, or as portions of an application-specific integrated circuit.Thus, the example system is applicable to software, firmware, andhardware implementations.

In accordance with various embodiments of the present disclosure, themethods described herein are intended for operation as software programsrunning on a computer processor. Furthermore, software implementationscan include, but not limited to, distributed processing orcomponent/object distributed processing, parallel processing, or virtualmachine processing can also be constructed to implement the methodsdescribed herein.

The present disclosure contemplates a machine readable medium containinginstructions 324, or that which receives and executes instructions 324from a propagated signal so that a device connected to a networkenvironment 326 can send or receive voice, video or data, and tocommunicate over the network 326 using the instructions 324. Theinstructions 324 may further be transmitted or received over a network326 via the network interface device 320.

While the computer-readable storage medium 322 is shown in an exampleembodiment to be a single medium, the term “computer-readable storagemedium” should be taken to include a single medium or multiple media(e.g., a centralized or distributed database, and/or associated cachesand servers) that store the one or more sets of instructions. The term“computer-readable storage medium” shall also be taken to include anymedium that is capable of storing, encoding or carrying a set ofinstructions for execution by the machine and that cause the machine toperform any one or more of the methodologies of the present disclosure.

The term “computer-readable storage medium” shall accordingly be takento include, but not be limited to: solid-state memories such as a memorycard or other package that houses one or more read-only (non-volatile)memories, random access memories, or other re-writable (volatile)memories; magneto-optical or optical medium such as a disk or tape; andcarrier wave signals such as a signal embodying computer instructions ina transmission medium; and/or a digital file attachment to e-mail orother self-contained information archive or set of archives isconsidered a distribution medium equivalent to a tangible storagemedium. Accordingly, the disclosure is considered to include any one ormore of a computer-readable storage medium or a distribution medium, aslisted herein and including art-recognized equivalents and successormedia, in which the software implementations herein are stored.

Although the present specification describes components and functionsimplemented in the embodiments with reference to particular standardsand protocols, the disclosure is not limited to such standards andprotocols. Each of the standards for Internet and other packet switchednetwork transmission (e.g., TCP/IP, UDP/IP, HTML, HTTP) representexamples of the state of the art. Such standards are periodicallysuperseded by faster or more efficient equivalents having essentiallythe same functions. Accordingly, replacement standards and protocolshaving the same functions are considered equivalents.

The illustrations of embodiments described herein are intended toprovide a general understanding of the structure of various embodiments,and they are not intended to serve as a complete description of all theelements and features of apparatus and systems that might make use ofthe structures described herein. Many other embodiments will be apparentto those of skill in the art upon reviewing the above description. Otherembodiments may be utilized and derived therefrom, such that structuraland logical substitutions and changes may be made without departing fromthe scope of this disclosure. Figures are also merely representationaland may not be drawn to scale. Certain proportions thereof may beexaggerated, while others may be minimized. Accordingly, thespecification and drawings are to be regarded in an illustrative ratherthan a restrictive sense.

Such embodiments of the inventive subject matter may be referred toherein, individually and/or collectively, by the term “invention” merelyfor convenience and without intending to voluntarily limit the scope ofthis application to any single invention or inventive concept if morethan one is in fact disclosed. Thus, although specific embodiments havebeen illustrated and described herein, it should be appreciated that anyarrangement calculated to achieve the same purpose may be substitutedfor the specific embodiments shown. This disclosure is intended to coverany and all adaptations or variations of various embodiments.Combinations of the above embodiments, and other embodiments notspecifically described herein, will be apparent to those of skill in theart upon reviewing the above description.

The Abstract of the Disclosure is provided to comply with 37 C.F.R. §1.72(b), requiring an abstract that will allow the reader to quicklyascertain the nature of the technical disclosure. It is submitted withthe understanding that it will not be used to interpret or limit thescope or meaning of the claims. In addition, in the foregoing DetailedDescription, it can be seen that various features are grouped togetherin a single embodiment for the purpose of streamlining the disclosure.This method of disclosure is not to be interpreted as reflecting anintention that the claimed embodiments require more features than areexpressly recited in each claim. Rather, as the following claimsreflect, inventive subject matter lies in less than all features of asingle disclosed embodiment. Thus the following claims are herebyincorporated into the Detailed Description, with each claim standing onits own as a separately claimed subject matter.

1. A computer-readable storage medium, comprising computer instructionsfor: retrieving a called party number and a calling party number from acommunication session; identifying a calling party according to thecalling party number; identifying a called party according to the calledparty number; retrieving calendar information of the called party;detecting in the calendar information a scheduled event associated withthe calling party; retrieving presence information of the called party;and detecting a conflict with the scheduled event according to thepresence information of the called party.
 2. The storage medium of claim1, comprising computer instructions for informing the calling party ofthe conflict.
 3. The storage medium of claim 1, comprising computerinstructions for determining an alternative time for the scheduledevent.
 4. The storage medium of claim 3, comprising computerinstructions for: proposing the alternative time for the scheduled eventto the calling party; detecting from the calling party an acceptance tothe alternative time; and rescheduling the scheduled event at thealternative time.
 5. The storage medium of claim 1, comprising computerinstructions for: receiving from the calling party an emergency accesscode; and redirecting the communication session to a communicationdevice of the called party according to the presence information.
 6. Thestorage medium of claim 1, comprising computer instructions for:detecting a communication priority level for the calling party; andredirecting the communication session to a communication device of thecalled party according to the presence information and the communicationpriority level.
 7. The storage medium of claim 1, wherein the calendarinformation is retrieved from a calendar server, wherein the presenceinformation is retrieved from a presence server, and wherein theidentity of the called party is retrieved from a contact book server. 8.The storage medium of claim 1, wherein the computer-readable storagemedium operates in an IP Multimedia Subsystem (IMS) communicationsystem.
 9. A proactive scheduler, comprising a controller element todetermine a scheduling conflict between a called party and a callingparty according to calendar information of the called party and presenceinformation of the called party.
 10. The proactive scheduler of claim 9,wherein the controller element informs the calling party of saidscheduling conflict over a communication session with a communicationdevice of the calling party.
 11. The proactive scheduler of claim 9,wherein the controller element: determines an alternative time tomitigate the scheduling conflict; and proposes said alternative time tothe calling party over a communication session with a communicationdevice of the calling party.
 12. The proactive scheduler of claim 11,wherein the controller element: detects an acceptance to the alternativetime supplied by the communication device of the calling party; andreschedules the scheduling conflict at the alternative time.
 13. Theproactive scheduler of claim 9, wherein the controller element: receivesover a communication session with a communication device of the callingparty an emergency access code; and redirects the communication sessionto a communication device of the called party according to the presenceinformation.
 14. The proactive scheduler of claim 9, wherein thecontroller element: retrieves communication preferences for the callingparty; determines from said communication preferences that calls fromthe calling party are to be directed to the called party; redirects acommunication session with a communication device of the calling partyto a communication device of the called party according to the presenceinformation.
 15. The proactive scheduler of claim 9, wherein thecontroller element: retrieves the calendar information from a calendarserver; and retrieves the presence information from a presence server.16. The proactive scheduler of claim 9, wherein the proactive scheduleroperates in an IP Multimedia Subsystem (IMS) communication system.
 17. Apresence system, comprising a controller element to present a schedulerpresence information of a called party to determine a schedulingconflict between a calling party and the called party according tocalendar information associated with the calling party and called partyand said presence information.
 18. The presence system of claim 17,wherein the presence information is utilized by the scheduler todetermine an alternate time that mitigates the scheduling conflict. 19.The presence system of claim 17, wherein the presence information isutilized by the scheduler to select a communication device of the calledparty having a desired probability of achieving communications with thecalled party.
 20. The presence system of claim 19, wherein the schedulerredirects a communication session with a communication device of thecalling party to the selected communication device of the called party.21. The presence system of claim 17, wherein the presence systemoperates in an IP Multimedia Subsystem (IMS) communication system.